Method of sinking wells by means of explosive charges



Aug;4; 1959 L. BORINS ETAL METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CI'IARGES l5 Sheets-Sheet 1 Original Filed Feb. 21, 19 57 m 56.1w wmmm mB J u 0 a 0 LM V. B

W A T T ORNE Y.

Aug. 4, 1959 L. BORINS ETAL 2,397,756,

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES I Original Filed- Feb. 21. 1957 7 1s Sheets-Sheet 2 Fig.3.

INVENTURS Louis BONDS,

aurlce ll 0 Aug. 4, 1959 L; BORINS ETAL 2,897,756

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 F1 Q4; I 4 25 v 38- l5 Sheets-Sheet 3 R3 Louis Borjns, BY Maurzceh. Slud.

- MauricQJ ub/coff,

Aug. 4, 1959 L. BORINS ETAL 2,397,756

. METHOD OF SINKING' WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 4,

Maurice .Zubkoff, K C ATTORNEY.

Aug. 4, 1959 BQRINS ETAL 2,897,756

METHOD OF smxzuc WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 6 i N IV 74 20 I/IIII/ INl-EZ VTORS Lows Borms BY Maurice/1f. Slua,

Wublcofi,

ATTORNEY.

Aug. 4, 1959 L. BORlNS ET AL 2,897,756

' METHOD OF smxmc WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 7 ll ll IN/ENTQRS Lou1 s Borms,

BY NGUIlCQHS/Ld,

Maurie J. Zu Jroff,

W ATTORNEY.

Aug. 4, 1-959 L. BORINS ETAL 2,897,756

METHOD OF smxmc WELLS BY MEANS OF EXPLOSIVE CHARGES Original File d Feb. 21, 1957 15 Sheets-Sheet a INVENTORS Lows Borms. BY gaurgcei fig d aunca u 0 SW A Tommi g- L. BORINS ETAL 2,897,756

- METHOD OF smxmc; WELLSBY MEANS OF EXPLOSIVE CHARGES ori inal Filed Feb. 21, 1957 i 15 Sheets-Sheet 9 8o y Y 81%- INVENTORS LouzsBorms BY MCZUFICQHSJLld,

Mauri izubkoff, M

. ATTORNEY Aug.- 4, 1959 I L. BQRINS ETAL 2,897,755

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21', 1957 15 Sheets-Sheet 1o INVENIORS Lows Borms.

'BY Maurjcehfislud,

MaurzceJ. ublcoff,

o-ul'bw ATTORNEY.

Aug. 4, 1959 BQRINS ET AL 2,897,756

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet ll .FiQ24 y F 1Q 25. Fig).

- ja I 6 13%: W 108 126A m 1% 127 119 28 a b; I. Z A 15 1 6 v 15 2. f 7 7 46 Louis Borjns, BY NauriooHSJud, Maurz'c .Zublcoff,

ATTORNEY.

INV NTOR.

4, 1959 L.'BORINS ET AL 2,897,756

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 15 Sheets-Sheet 12 NVENTpRS Lem; Borms, BY McIurmQHSJud,

Mu (8 ATTORNEY.

. Mauricelz'ubkoff,

ug- 4, 1959 L. BORINS ETAL METHOD OF smxmc WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 F1 Q. 21. r 7

138 T56 E64J1155152 142 141: 1

124 F1928. V a 135 14 {1Q 15 Sheets-Sheet 13 42s 5 Y 64 1 51 145 145 151 .f 147 INVENIORS L0 L115 Borms.

BY MauricoH.5]ud,

Mgngf zubkoffi ATTOmEY.

Aug. 4, 1959 L. BORINS ETAL 2,897,756

METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. '21, 1957 l5 Sheets-Sheet 14 154 INVENTORS Louis Borjns, BY MQUTI'CQHSJUCZ,

MazzricgJZubkofi,

ATTQRNEY.

' Aug; 4, 1959 L. BORINS- ET AL METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Original Filed Feb. 21, 1957 l5 Sheets-Sheet l5 f i fl I @5 1 468 9 fi I A 4 J156 T162?6 1 62 1 86 1 k 156 I INVENTOR.

Louis Borins. BY MauriceH.Slud,

Ma url'cal Zublcoff,

2,897,756 Patented Aug. 4, 1959 METHOD OF SINKING WELLS BY MEANS OF EXPLOSIVE CHARGES Ilouis Borins, Buffalo, Maurice H. Siud, Depew, and Maurice J. Zubkofi, Tonawanda, N.Y., assignors to Randal Tool Company, Inc, Bufialo, N.Y., a corporation of New York Original application February 21, 1957, Serial No. 638,749. Divided and this application March 21, 1957, Serial No. 647,716

10 Claims. (Cl. 102-21) This application is a division of our application Serial No. 63 8,749.

This invention relates to a method of sinking wells by means of explosive charges.

Excessive expense, as to money and time, is involved in the advancement of the well bore through hard impervious rock strata by means of known drilling equipment and methods. Because of such expense recourse has been had to the use of shaped explosive charges for advancing the well bore through that particular impervious stratum known as cap-rock which immediately overlies the productive sands, the availability of such charges for this purpose being established.

The known practice, in connection with the necessary repetition of the cycles of operation, involves a number of factors of substantial expense in respect to time and cumulative items of equipment. Thus each cycle of operation is limited to the detonation of a single heavy,

, powerful and costly charge to effect a penetration of a number of feet. The detonation causes the destruction of the shell, associated parts and the shock absorbing feature with the resultant necessity of withdrawing the undestroyed parts from the well bore, reloading with a new shell, reconnecting a new shock absorbing feature for a succeeding cycle of operation, and again lowering the equipment through the well bore to the advanced point of detonation. In addition flushing operations necessary for the removal of the detritus must be carried 7 out in an interval subsequent to a cycle of operation of the apparatus; and interim recourse to the use of conventional reaming equipment may, from time to time, be advisable or necessary.

In geological formations which contain a stratum of productive sands the stratum is immediately overlaid by a hard stratum of impervious cap-rock above which in the majority of instances there is a mass of earth which may be composed of soft components and components at least equal in hardness to cap-rock. Where this mass may be free from hard rock strata it presents no serious obstacle to the use of standard drilling equipment. Where hard strata (other than hard cap-rock) are encountered the difliculty and expense of advancing the well bore is the same as in the advancement of the well bore through hard cap-rock. Even in the soft strata or body of this mass the known shaped charge apparatus, although obviously having much greater penetrating power than it does in the hard rock strata, is not economically available for advancing the well bore in that certain of the factors of expense set forth in the preceding paragraph make the expense much more costly than the use of standard drilling equipment, the increment of the comparative cost being proportionate to the depth of the soft strata or body.

The object of the invention is to provide a method which in a single cycle of operation utilizes a plurality of shaped charges sequentially detonated, each shaped charge being of wafer-like form and having a multiplicity .of .directionalizing. recesses, preferably uniformly dis- 2. tributed, the method being available for advancing the well bore from the surface and including the use of blasting charges arranged with the shaped charges as parts of a series of explosive charges and detonated in sequential relation to the shaped charges, and provision during the period of the detonations for flushing from the'well bore the detritus resultant from the detonations.

The method of the invention is practiced by the apparatus shown in the drawings and which forms the subject of our application Serial No. 63 8,749.

The method contemplates and includes a unitary explosive charge carrier composed of suitable frangible material, preferably dielectric and preferably molded from a thermosetting plastic such as rubber or a phenol condensation product, which is shattered, i.e., pulverized, by the detonation. The carrier is fashioned to support the charge and in the case of shaped charges is also fashioned to position the charge in proper standoff relation to the target. In the case of blasting charges the charge may be supported by the carrier for deposit closely adjacent or in substantially adjoining relation to the target.

Each charge carrier is of generally cylindrical form and the part which projects above the explosive charge is rutilized for its support in the magazine and in the charge transfer means. Each carrier for a shaped charge includes a charge-supporting web located at an intermediate elevation and which also protects the charge against water, either as used for flushing or as encountered in the well sinking operation. Each carrier for a blasting charge preferably includes a similar web located at or near its lower end. In the case of shaped charges each carrier is formed with an annular skirt which projects for a suitable distance below the web and rests upon the target, thereby to position the charge in the appropriate stand-off relation to the target. Each carrier includes an annular vertical Wall which in the construction preferred is of externally tapering outline and is otherwise formed to receive in nesting relation the lower portion of the carrier immediately above.

The shaped charge and the frangible charge carriers are of novel and advantageous construction and are the subject of our pending application Serial No. 736,178, the shaped charges being of wafer-like form and characterized by a multiplicity of uniformly distributed downwardly facing directionalizing recesses which simultaneously generate penetrating jets. The shaped charges may be said to be wafer-like in that in thickness they are quite shallow as compared with shaped charges heretofore known for well sinking or well shooting and the area through which the directionalizing recesses are distributed is many times in excess of their thickness. The penetrating jets resultant from the detonation of a charge shatter the hard rock uniformly for a distance, according to the predetermined strength of the charge, of the order of from two to six inches and advance the well bore in cylindrical outline through such distance. It is preferred, and in accordance with the invention, that the recesses adjacent the periphery of the charge have their axes at a very slight outward and downward inclination, e.g., of the order of one or two degrees in order to insure that the diametrical dimension of the well bore shall be ample for the free movement of the apparatus. Beyond the distance of effective penetration there will be a series of tapering openings whereby the bottom of the well bore will present a series of ridges which are obliterated by the succeeding detonation, either of a shaped charge or a blasting charge. The size and weight of the shaped charges are determined in accordance with the particular local conditions that may be encountered. Generally speaking, the diametrical dimension is of the order of five and one half inches and the remaining charges.

the thickness or depth is within a range of the order of from one-half inch to somewhat more than two inches. An integral shaped charge of one-half inch depth has a weight of the order of one-half pound and the maximum weight for charges of greater depth, with allowance for the increase in the dimensions of the directionalizing recesses, is of the order of one pound.

The blasting charges are in the form of an integral body of explosive material and, according to local conditions, have a depth within a range of the order of onehalf inch to one inch and weight within a range of the order of one-half pound to one pound.

When the stratum of oil bearing sands is reached it may be of economic advantage, depending upon local conditions, to increase the diameter of the well bore For this purpose shaped charges are used having peripheral directionalizing recesses with their axes directed laterally in addition to the multiplicity of directionalizing recesses open to the lower face of the charge with the result that upon detonation the well bore is. both deepened and widened. With shaped charges having a diametrical dimension of the order of five and one-half inches the wellbore within the cap-rock and the overlying ea will have a diameter somewhat in excess of six inches. The increase of the diameter in the oil hearing stratum may be in excess of twice the diameter of the well bore in the overlying mass.

The shaped charges, preferably, but not necessarily, of any suitable high brisance material, are detonated, in accordance with known practice, by an initiating charge activated by the ignition (from electrical sources) of an explosive fuse such as primacord, the initiating charge as associated with a shaped charge of integral character being preferably of disc outline and arranged within the fuse in adhering relation to the explosive charge. Each explosive charge is detonated by a delay type igniter following its deposit upon the target and during the return movement of the charge transfer means.

In the use of the apparatus the magazine is loaded at the surface with the charges in superposed relation to such extent, i.e., its full capacity or less, as may be determined upon by the operator. This determination also includes the selection and sequential arrangement of the charges; for example the detonations of two or more of the shaped charges in immediate succession may be required followed by detonation of one or more blasting charges, which in turn may be followed by further detonations of shaped charges; or, according to particular conditions, the loading may be confined to blasting charges; or the loading may require as the bottom charge or charges one or more shaped charges formed -to enlarge the well bore in the stratum of oil bearing sands. As initially loaded the lowermost charge will be held against displacement and will form the support for As the lowermost charge is delivered to the transfer means the remaining charges are advanced a step in the magazine and the charge which then becomes the lowermost charge is similarly held against displacement and similarly supports the remaining charges, the step-by-step delivery of the charges from the magazine being continued until the magazine is exhausted;

The permanent unit includes a shell which provides the magazine, its lower portion carrying a surrounding sleeve in spaced relation which delimits an annular vertical way external of the shell and the charge transfer means (also a part of the permanent unit) is vertically movable inthe way and projects below the shell, its projecting portion being formed with an inwardly extending annular flange corresponding in internal diameter to themaximum external diameter of the charge carrier. The flange ofthe charge transfer means receives and supports a charge carrier upon its release from the magazine and preferably, but not necessarily, has a vertical extent at least equal to the vertical extent of the explosive charge carriers.

As the depth of the well bore increases the stretch of the supporting cables proportionately increases under the weight of the apparatus with the result that at depths, for example in excess of one hundred feet, the stretch of the cables is to such extent that it may not be possible to determine with reasonable accuracy the distance of the apparatus from the target. For this reason, when the apparatus is operating at any such depth and is returned to the surface for reloading the preferred practice is to move the charge transfer means to its lowermost position prior to the lowering of the apparatus into the well bore and with the lowermost explosive charge of the complete series remaining in the magazine. The apparatus is then lowered until the lower face of the flange of the charge transfer means contacts the target, the further downward movement of the shell being thereby arrested and any resultant slack of the cables being taken up. Thereby the charge transfer means insures the safe elevation of the shell above the explosive charge at the time of the detonation. After the empty charge transfer means has made contact with the target the apparatus is held in its lowered position and the transfer means is returned to its upper position where it receives the lowermost explosive charge carrier. The charge transfer means is then moved downward, carrying the explosive charge with it, until its lower face again makes contact with the target. The explosive charge carrier is then released and the charge transfer means returned to its upper position where it receives the then lowermost explosive charge carrier. After the charge carrier is released from the charge transfer means and during the return of the charge transfer means to its upper position the firing circuit is automatically conditioned for operation and the charge is exploded. During the remainder of the cycle of operation the apparatus is lowered after each detonation through a step approximately equal to the extent of the penetration resulting from the previous detonation, the extent of such step being a matter of inches. It follows that the charge transfer means in each of its succeeding downward movements during the remainder of the cycle will deliver a charge carrier from the magazine and deposit it upon the target.

An alternative practice which may be followed after the reloading of the apparatus at the surface is to maintain the charge transfer element in its raised position during the lowering of the apparatus into the well bore, 1

and to deliver the lowermost charge of the complete series into the charge transfer means prior to or during the lowering of the apparatus. In this case when contact is made with the target the apparatus is raised to an extent corresponding to a stroke of the charge transfer means, i.e., to the extent to which the charge transfer means in its lowered position projects beyond the shell. When the apparatus is raised to such extent the charge transfer' means may then be lowered to deposit the charge in detonating relation to the target, the cycle of detonating operations being then continued in the manner above described.

Apparatus for practicing the method of the invention and the steps and characteristics of the method are illustrated in the accompanying drawings in which:

Figures 1 to 1d inclusive are schematic views illustrating the successive steps of operation involved in the detonation of an initial shaped charge when hard impervious rock stratum is encountered.

Figure 1' is an elevation, partly in section, which as- 5 which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means, immediately following its initial contact'with the target, in its uppermost position inwhich it has received the lowermost charge carrier from the magazine.

Figure 1b is a similar fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means, bearing a charge carrier, in its lowermost position in which the charge carrier is deposited upon the hard rock stratum for detonation of the charge.

Figure 1c is a similar fragmentary elevation, partly in section, which shows the apparatus with thegshell in the position shown inFigure 1 at the time when the charge transfer means, having deposited the charge carrier upon the target for detonation of the charge, is in movement toits uppermost position to receive a succeeding charge carrier from the magazineflhe deposited charge carrier being shown resting upon the target.

Figure 1d is a similar fragmentary elevation, partly in section, which shows the apparatus with the shell in the position shown in Figure 1 but with the charge transfer means in its uppermost positionand as having received a succeeding charge carrier from the magazine, this figure assuming the detonation of the preceding charge and showing the resultant extension of the well bore into the hard rock stratum.

Figure 2 is a fragmentary elevation, partly in section, which assumes the detonation of a preceding charge and the downward movement of the apparatus for a distance corresponding to the resultant extension of the well bore with the shell and the charge transfer means in the same relation to one another and to the hard rock stratum which is shown in Figure 1b, it beingunderstood that the immediately succeeding steps of operation are in accordance with the showing of Figures 1c and 1d. V

" Figures 3 and 4, considered'conjointly, show the apparatus in vertical central section, Figure 3 showing the upper portion of the apparatus and Figure4 its'lower portion with theexplosive charge transfer means in its raised position relatively to the shell.

Figure 5 is a partial vertical central section of the apparatus with the explosive charge transfer means in its lower position relatively to the shell.

Figure 6 is a horizontal section on the line 6-6 of Figure 3 with a cover plate partly broken away to expose to view certain underlying parts.

Figure 7 is a horizontal section-on the line. 7-7 of Figure 3. i

Figure 8 is a horizontal section on the line 8-8 of Figure 3. i

Figure 9 is a horizontal section on the line 9-9 of Figure 4.

- Figure 10 is a horizontal section on the line 10'-l0 of Figure 4. I

V Figure 11 is a horizontal section on the .line 1111 of Figure 4.

Figure. 12 is a horizontal section on the line 12--12 of Figure 4.

Figure 13 is a partial vertical diametrical section on an enlarged scale of the shaped charge carrier and the shaped charge, together with the lower portion of the charge transfer means.

Figure 14 is a similar view in which the carrier is formed for the support of a blasting charge, the plane of the section being sixty degrees distant from the plane of the section shownin Figure 13. ,Figure 15 is a perspective sectional view of one of a plurality of similar valves by which air as the operating fluid is admitted into the pressure way above the charge transfer means.

Figure 1.6 is an enlarged fragmentary vertical sectional :viewin the same plane as Figure 5 showing in closed powith the upper and intermediate shell sections in separated relation and showing more particularly their companion connecting elements and the electrical contacts at the lower end of the upper shell section and the upper end of the intermediate shell section.

Figure 20 is a tail perspective view, partly in section, on an enlarged scale, of one of a plurality of valves shown in Figures 4, 5 and 9 :for controlling the flow of air through certain passages, the valve in this figure being in its open position which is shown in Figure 5.

Figure 21 is a fragmentary horizontal sectional View on the line 21-21 of Figure 16 showing one of a plurality of similar air by-passing valves used in the venting operation.

Figure 22 is a detail perspective view, partly broken away and in vertical section, of the charge transfer means.

Figure 23 is a detail fragmentary perspective view partly broken away and showing the relationship between the lower portion of the shell and the sleeve in surrounding relation to the shell and which delimits an annular way external of the shell in which the charge transfer carrier is movable.

Figure 24 is a wiring diagram showing the detonating circuit as conditioned to effect the detonation.

Figure 25 is a developed vertical section showing electrical cable sections in the several shell sections and the charge transfer means and also showing the electrical con nections between the wires. Figure 26 is a vertical section in a plane radially intersecting the section shown in Figure 25.

Figure 27 is a central transverse section of a shaped charge and its carrier, this figure assuming that the charge is an integral body of explosive material and that the directionalizing feature consists of conical recesses.

Figure 28 is a central transverse section of a blasting charge and its carrier.

Figure 29 is a partial bottom plan view of the shaped charge shown in Figure 27.

Figure 30 is a partial plan view of a shaped charge consisting of an integral body of explosive material wherein the directionalizing feature consists of concentric grooves of inverted V-shape in section.

Figure 31 is a partial transverse sectional View on the line 3131 of Figure 30.

Figure 32 is a bottom plan view of a shaped charge consisting of an integral body of explosive material wherein the directionalizing feature consists of radially arranged grooves of inverted V-shape in section.

Figure 33 is a partial transverse section on the line 3333 of Figure 32.

Figure 34 is a partial central transverse section of a shaped charge which is formed to enlarge the well bore in the stratum of oil bearing sands, the showing of the shaped charge inthis figure being applicable either to conical recesses or annular grooves as the directionalizing feature.

Figure 35 is a partial side elevation of a shaped charge formed to enlarge the well bore in the stratum of oil bearing sands and wherein the directionalizing feature for sinking the well bore vertically consists of the radial grooves shown in Figures 32 and 33.

Figure 36 is a plan view of a shaped charge which shows more particularly the form of the explosive fuse and its relation to the initiating charge and the electrically actuated delay type igniter.

- the line 3838 of Figure 37, this figure also showing by broken lines the mounting of the charge in the charge carrier.

The operating unit includes a shell 1 of cylindrical form which carries sundry associated parts and provides a magazine for the explosive charge carriers 2 (Figures 3, 4 and arranged in superposed relation and provided in a predetermined number. The shell is preferably composed of upper, intermediate and lower cylindrical sections (Figure 1) 1a, 1b and 1c, respectively, connected in abutting relation by any suitable quick releasable devices, e.g., the bayonet lugs 3 at the lower ends of the sections 1a and 1b and the companion slots 4 at the upper ends of the sections 1b and 1c. The upper section 1a carries a distributor and the lower section is associated with the charge transfer means, both to be later described in detail. The sections 1b and 1c conjointly provide the magazine, and the sections 1b are made of varying lengths from which a selection may be made in order that the magazine capacity may be in accordance with prevailing conditions.

The shell 1 (Figure 3) is detachably connected at its upper end to a top plate 5 and is raised and lowered by means of cables 6 having terminal loops 7 threaded through eye members 8 bolted as at 9 to the top plate 5. The movable parts of the operating unit are power actuated, preferably by compressed air conveyed from an external source by a flexible hose 10 having a suitable connection 11 externally of the unit to a pipe section 12 which extends into the unit through the plate 5. The flushing of the rock detritus is preferably effected by a flushing fluid of any suitable character which for brevity and convenience is herein referred to as water. The water is pumped under suitable pressure from a source at the surface and is conveyed by a flexible hose 13 hav ing a suitable conenction 14 externally of the unit to a pipe section 15 which extends into the unit through the plate 5. The cable 16 for the electric wires of the circuit by which the squib is ignited extends into the unit through the top plate 5. The section 1a carries in detachable relation a distributor 17 for the air conveyed by the hose 10 and the Water conveyed by the hose 13.

The distributor 17, in the form of a cylindrical block, is formed with a vertical passage 18 which may be called a supply passage for the operating fluid. The passage 18 is in open communication at its upper end with the pipe section 12 and at its lower end with a horizontal continuation 19 which extends radially to, and communicates with, an opening 37 located centrally of the distributor 17. The opening 37, as will be later described in detail, forms part of a flow passage from which air under pressure is delivered into the pressure space P at the upper end of the magazine M in which the explosive changes are arranged. The opening 37 is also utilized as a manifold for the distribution of air via radial passages (Figure 7) 20a, 20b, 20c, 20d and 20a to a number of vertical air flow passages formed in the wall of the shell and which will be described in detail at a later point. A passage 21 of similar function extends radially outward from the passage 18 and communicates with one of the vertical air flow passages in the shell. The distributor 17 (Figure 3) has a recess in its upper face which provides a water inlet chamber 22 closed by a cover plate 23 fitted in a countersunk recess and secured in any suitable manner, as by spot welding. The pipe section 15 is connected to the cover plate 23 and is normally in open communication with the chamber 22.

The cables 6 in their functions of raising, lowering and supporting the operating unit are controlled by a suitable Windlass (not shown) located at the surface. The air hose .10, water hose 13 and electric cable 16 are severally mounted on suitable reels (not shown) located at the surface. Since the air hose 10, water hose 13 and cable 16 differ in diameter from one another and from the cables 6 any suitable provision is made in accordance with known engineering practice for coordinating the rate of rotation of the reels to the rate of rotation of the Windlass for the cables 6 whereby these several flexible elements will have the same rate of upward and downward movement.

The water inlet chamber 22 discharges through a series of passages 24 in the distributor 17 into a vertical flush pipe 25 detachably connected to the distributor 17 from which it extends for the remaining length of the unit, the pipe 25 being open at its lower end and of any suitable diameter, e.g., the same diameter as the hose 13 and pipe section 15. The water is pumped under suitable pressure through the hose 13 and pipe section 15 and, discharging from the pipe 25, flows into the lower end of the well bore W whence, carrying with it in suspension the fragmented and pulverized rock detritus, it flows upward to the surface through the space S between the well bore and the unit, being conveyed at the surface to a disposal basin (not shown).

The gallonage of water required per unit of time for the flushing operation will, of course, vary with different operating conditions including the depth at which the unit may be working. The amount of water required or proper for a particular operating condition is determined by a suitable flow regulating valve. As shown, and now considered preferred, the water flow regulating valve (Figures 3 and 6) consists of a plate '26 of disk form mounted for turning movement about its axial center upon the base of the inlet chamber 22 and having openings 27 for total or partial registry with the upper ends of the passages 24, the amount of water delivered to the pipe 25 being proportionate to the degree of registry. The positional adjustment of the valve 26 is made in accordance with prevailing conditions at any position of the unit in the well bore, preferably by an electric motor 28 mounted upon the cover plate 23. The regulation of the flow of flushing water through the pipe 25 by the adjustment of the position of the valve 26 as incorporated with the unit results in the rate of flow of flushing water through the pipe 25 being determined independently of friction losses in the water supply hose 13. The shaft 29 of the motor 28 extends into the water inlet chamber 22 and is journaled at its lower end in the distributor 17, the shaft carrying a spur gear 30 adjacent the base of the chamber 22. The plate 26 is formed with a series of peripheral teeth 31 (Figure 6) in mesh with the spur gear 30. The position of the plate 26 is indicated to the operator at the surface by a well known telemetric dial mechanism (not shown) which is sufiiciently exemplified by the patent to Riggs No. 665,133 of January 1, 1901 and is in electrical association with the motor 28, the form of the dial mechanism and the manner of its electrical association with the motor being well known for use where the positional adjustment of a concealed part is to be indicated to the operator in charge. The dial mechanism, of course, informs the operator of the prevailing adjustment of the position of the plate 26 and enables him to determine .the direction and extent of its movement when a change may be required in the gallonage of water flowing through the pipe 25.

In the event that a back pressure should be encountered sufficiently high to cause resurgence of the water in the pipe section 15 and hose 13, or otherwise to put an undue load on the pump, it is desirable that the flow of water he cut off until the condition is relieved. For this purpose a check valve 32 (Figure 3) is located in alining relation below the lower end of the pipe section 15 and Urged upward by a loading spring 33, Figure 3 assuming the valve 32 to be held openby the pressure of the water discharging from the pipe section 15. The valve 32 has a central depending stem 34 whichprovides a pivot about which the valve 26 may be turned and, projecting through a central opening in the valve, is fitted loosely in a recess in the distributor 17. The pressure of the spring 33 may be relied upon to hold the plate 26 in seated relation upon the base of the recess 22.

The shell parts 1b and 1c conjointly provide the magazine .M for the explosive charge carriers 2, these having central openings 35 (Figures 3, 4, 5, 27 and 28) which accommodate the pipe 25 and aline with other accommodating openings in parts associated with the charge carriers as will be later described in detail. The shell parts 121 are made of varying lengths to enable the selection of the particular magazine capacity which will accord with prevailing conditions. It is preferred that the charge carriers as a series be at all times under pushing pressure. The pressure medium is preferably compressed air delivered from the passage 19 into the upper portion of the magazine and acting upon a horizontal follower or pusher plate 36 slidably mounted in the magazine and having a direct bearing upon the uppermost carrier of the series. The air flow passages for the delivery of air into the magazine includes the opening 37 in the distributor 17 of suitably greater diameter than the pipe 25 and which communicates with and extends downward from the passages 19 and 20a, 20b, 20c, 20d and 20:2. The wall of the opening 37 is formed with an annular rabbeted recess extending to the underface of the distributor 17 in which is fitted the upper end of a pipe 38 arranged in spaced concentric relation to the pipe 25 and also accommodated in the openings 35 and the associated alining openings. The pipes 38 and 25 delimit an annular air flow passage 39, the upper end of which is constituted by the annular wall of the opening 37. The pipe 38 extends from the distributor 17 preferably for the remaining length of the unit and the air passage 39 is closed at its lower end by a ring 40 (Figure interposed between the pipes 38 and 25 and also serving to brace these pipes to one another.

The pipe 38 has in its upper portion a series of openings 41 through which the air flows from the passage 39 into the pressure space P of the magazine. The follower 36 has a central opening in surrounding relation to the pipe 38 and is preferably formed at the perimeter of this opening and at its periphery with raised flanges 42 and 43 which are respectively in suitable contact with the pipe 38 and the inner wall of the shell 1 and serve both as guides for the follower 36 and also to prevent undue loss of air from the pressure space P.

The explosive charge carriers 2 are supported by a series of movable detents 44 (Figures 5, 11, 14 and 18) provided at the lower end of the shell 1 and normally engaging the lowermost carrier 2 in the magazine, the detents 44 being operated to disengage the lowermost carrier at the time when it is to be released from the magazine and deposited in the charge transfer means. Immediately after the release of the lowermost carrier the detents 44 are returned to their normal positions in readiness to engage the immediately succeeding carrier which then becomes the lowermost carrier of the series. The discharge of each lowermost carrier from the magazine and the movements of the series of carriers in stepby-step fashion upon such discharges are effected by the downward movement of the follower 36 under the pressure of air in the magazine space above.

When the last charge of the series has been detonated the unit is brought to the surface for reloading (the air and water supply of course being cut off at the time) and the shell sections separated. If the number of charges required for the succeeding cycle remains unchanged a new series or clip of charges may be placed in the section 1b with the follower plate 36 resting upon the uppere to most charge and when the sections 1b and 1c are connected the clip will drop until the lowermost charge is engaged by the detents 44; or, as a time saving measure, a duplicate section 1b containing the same number of charges (held against displacement by removable tapes) may be substituted. if the number of charges required for the succeeding cycle should vary from the number required for the preceding cycle a section 1b of greater or less length containing the determined number of charges is substituted. Thereupon the three sections are again connected and the unit is lowered into the well bore for a repetition of the cycle of operations. The length of the pipes 25 and 38 of course accord with the length of the shell.

If a magazine of greater capacity than that of a single section 1b of maximum capacity be desired two or more sections 1b may be connected together as a string, the follower plate 36 being of course arranged in the uppermost section 1b.

The charge transfer means 45 (Figures 4 and 5) is in the form of a cylinder having piston-like movement in an annular vertical way 46 at the lower end of the shell 1. The way 46 is open at its lower end and. is delimited by the shell and a spaced concentric sleeve 47 secured to the shell in any suitable manner. As shown the sleeve has an upward extension 48 of reduced internal diameter which adjoins the outer face of the shell and provides an internal annular shoulder 49, the sleeve having internal threads immediately below the shoulder 49. The shell 1 is provided at a suitable elevation with a circumscribing flange 50 against which the shoulder 49 abuts when the sleeve is properly positioned, the flange 50 having threads for engagement by the threads of the sleeve. A ring 51 is attached to the shell immediately below the flange 50 and is formed to provide housings for upwardly biased check valves 52 to be later described in detail, the lower face of the ring 51 constituting the upper face of the way 46.

The charge transfer cylinder 45 has at its upper end an annular head 53 which corresponds in thickness to the width of the way 46 and provides a piston responsive in downward movement to air under pressure admitted into the upper end of the way through the valves 52 and in upward movement to air under pressure admitted through certain air passages to be later described and reacting against an internal annular shoulder 54 (Figures 4, 5 and 22).

The cylinder 45 has at its lower end an inwardly projecting annular flange 55 which is preferably of the same vertical extent as the explosive charge carriers and receives the lowermost charge carrier from the magazine.

Each charge carrier, as supported within the flange 55, is deposited upon the bottom of the well bore at the completion of the downward movement of thecylinder 45. The downward movement of the cylinder 45 is positively limited by means later to be described in detail.

The charge carriers are supported within the flange 55 by a suitable number, e.g., three, of clamping dogs 56 (Figures 5, 12 and 13) mounted for radial movement in recesses 57 open to the inner face of the flange 55. The dogs 56 are normally biased inward by springs58 reacting against the bases of the recesses 57 and thereby have engaging and clamping contact with the vertical walls of the charge carriers 2. At their inner ends the dogs 56 have marginal flanges 59 against which air under pressure is delivered when the cylinder 45 reaches its lowermost position, the dogs 56 thereby being retracted and releasing the charge carrier'for support upon the bottom of the well bore. When the charge carrier is thus released the cylinder 45 moves upward to the position in which it receives the succeeding charge carrier from the magazine. The charge carriers 2 have a vertical annular wall 60 (Figures 13 and 14), the external face of which preferably has a slight downward taper and thedogs 56 have their engaging faces at an incline which conforms to the taper. 

